Simplify the following expression: $n = \dfrac{-3z^2 - 15z + 150}{z + 10} $
First factor the polynomial in the numerator. We notice that all the terms in the numerator have a common factor of $-3$ , so we can rewrite the expression: $ n =\dfrac{-3(z^2 + 5z - 50)}{z + 10} $ Then we factor the remaining polynomial: $z^2 + {5}z {-50} $ ${10} {-5} = {5}$ ${10} \times {-5} = {-50}$ $ (z + {10}) (z {-5}) $ This gives us a factored expression: $\dfrac{-3(z + {10}) (z {-5})}{z + 10}$ We can divide the numerator and denominator by $(z - 10)$ on condition that $z \neq -10$ Therefore $n = -3(z - 5); z \neq -10$